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Full text of "A new species of the genus Margarodes Guilding from buffalograss in Texas (Coccoidea, Margarodidae)"

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PROC. ENT. SOC. WASH., VOL. 68, NO. 3, SEPTEMBER, 1966 



237 



A NEW SPECIES OF THE GENUS MARGARODES GUILDING FROM 

RUFFALOGRASS IN TEXAS 

( COCCOIDEA, \ 1 ARGARODIDAE ) 1 

Burruss McDaniel, Jr., Department of Biology 
Texas College of Arts and Industries , Kingsville , Texas 

The North American members of the genus Margarodes Guilding 
have been reviewed in a previous publication by the author (Mc- 
Daniel, 1965). A recent collection of the grass species, Buchloe dacty- 
loides (Buffalograss), was infested with Antonina graminis (Rhodes- 
grass scale) on the crown and Margarodes sp. on the roots. The Mar- 
garodes specimens are close relatives of M. hiemalis Cockerell. Al- 
though only one of the specimens is a mature adult and a portion of 
the abdomen was damaged during collecting, it is apparent that they 
constitute a new species because of the absence of setae and pores on 
the conspicuous boss at the apex of the body, the eight segmented 
antennae, and the presence of only three abdominal spiracles. 

Margarodes dactvloides, n. sp. 

(Fig. i) 

Adult female. — Body oval-shaped; derm not chitinized. Dorsum with two 
types of setae, the long hair-like forms and the small microsetae, arranged in 
rows across the entire dorsal region of the body. Dorsal surface minutely 
papillose as shown in Fig. 1. Ventrally: antennae 8-segmented; segment 1 being 
larger than any other segment, with small microsetae scattered over its surface; 
segment 2 narrow, with small microsetae similar to those on segment 1; segment 
3 similar in shape to segment 2, macrosetae arranged near the margin of the 
anterior portion of segment; segment 4 short and broad, two times the length of 
segment 3, macrosetae arranged as in segment 3; segments 5 and 6 similar in 
size and shape with macrosetae at margins; segment 7 similar in shape to seg- 
ments 5 and 6 only larger, narrowing at base, macrosetae arranged in a circle 
around the anterior portion of the segment; segment 8 spherical with three 
elongated setae in addition to regular macrosetae found on other segments. Legs 
I strongly modified for digging, claw’ heavily sclerotized, inner surface not pitted 
with tooth-like structures as in M. hiemalis ; trochanter and coxa fused, there 
being on the inner surface an indented groove containing numerous long setae. 
Legs II and III smaller than legs I, modified for digging, claw’ without surface 
tooth-like structures, with same groove-like indentation and numerous long setae 
as found on legs 1. Thoracic spiracles similar to those of M. hiemalis , opening 
circular without a flap-like extension; tw’o internal disk pores present, absent in 
abdominal spiracles. Three pairs of abdominal spiracles, on segments 1, 2, and 
3. Abdominal segments with two types of setae; those slender or extremely 
elongated, arranged in row’s extending to center of body and entire length of 
body; and those short, spine-like, in center of body, scattered irregularly over 

1 This research was supported in part by legislative appropriation to Texas 
College of Arts and Industries for organized research. Grant No. 449-22. 



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PROC. EXT. SOC. WASH., VOL. 68. XO. 3, SEPTEMBER, 1966 




Margarod.es dactyloides n. sp. Fig. 1, left side showing taxonomic characters 
of dorsal view of female holotype; right side, taxonomic characters of ventral 
view. 





PROC. EXT. SOC. WASH., VOL. 68, NO. 3, SEPTEMBER, 1966 



239 



venter. Multilocular disk pores present on posterior abdominal segments, these 
with as few as 4 microloculi and as many as 10 microloculi within the pore. 
Abdomen with conspicuous stout boss broadly curved at apex and devoid of 
any hair-like setae and multilocular disk pores. Anal opening well-developed, 
anterior to boss and last abdominal segment, opening a circle with tube-like ex- 
tension having transv erse slit with internal lobe. 

Male . — Not available. 

Type. — The species described from a female holotype from Buchloe 
dcictyloides (Nutt.) Engelm (Buffalograss), collected 4 miles north 
of Scotland on highway 281, Archer County, Texas, June 21, 1965 
and deposited in the National Collection of Coccoidea, Washington, 
D. C. Paratypes, apparently immature forms, collected at type locality 
on same date as holotype deposited in the author s personal collection. 

Remarks. — Margarode s dactyloides may be separated from all other 
species of Margarodes found in North America by the absence of 
acorn-shaped setae. M. dactyloides and M. hiemalis are characterized 
by a boss-like extension of the last abdominal segment. They are 
separated by the reduced number of abdominal spiracles, there being 
thi *ee in M. dactyloides and six in M. hiemalis; the number of segments 
in the antennae, 8 in M. dactyloides and 7 in M. hiemalis; the arrange- 
ment of the hair-like setae; and the types of multilocular disk pores. 
In the key constructed by Morrison (1928), M. dactyloides keys to 
M. hiemalis. 



Key to Species of the Genus Margarodes Guilding 
found in North America 

1. “Acorn-shaped” setae present on body; multilocular disk pores with mi- 

crolocular ring containing macroloculi .... — 3 

“Acorn-shaped” setae absent; multilocular disk pores never with micro- 
locular ring, consisting of only microloculi or only macroloculi; apex 
of body with conspicuous stout boss broadly curv ed at apex — 2 

2. Abdomen containing 6 spiracles; antennae with 7 segments; tooth-like 

structures on claw hiemalis Cockerell 

Abdomen containing 3 spiracles; antennae with 8 segments; tooth-like 
structures on claws absent dactyloides, n. sp. 

3. Multilocular disk pores with only 2 macroloculi within circle of micro- 

loculi; thoracic spiracle with 5 macropores enclosing 5 micropores .... 

ineridionalis Morrison 

Multilocular disk pores with more than 2 macroloculi within circle of 
microloculi; thoracic spiracle with 6 macropores 4 

4. “Acorn-shaped” setae not anterior to abdomen, those on last 3 ventral 

segments strongly constricted apically; multilocular disk pores of two 
types: those with 4macroloculi in center of ring of microloculi, and 
those with only microloculi present ... rileyi Giard 



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PROC. ENT. SOC. WASH., VOL. 68, NO. 3, SEPTEMBER, 1966 



“Acorn-shaped” setae not restricted to abdominal segments, not con- 
stricted apically; multilocular disk pores of dorsum with 6 macroloculi 
within circle of microloculi morrisoni McDaniel 

References 

McDaniel, B. 1965. North American species of the genus Margarodes Guilding, 
with a description of a new species found in Texas. Proc. Ent. Soc. Wash. 
67: 15-23. 

Morrison, H. 1928. A classification of the higher groups and genera of the 
coccid family Margarodidae. U.S. Dept. Agr. Tech. Bull. 52: 72-78. 



THE NEARCTIC DORYCTINAE, III. THE GENUS 

CALLIHORMIUS ASHMEAD 

( Hymenoptera: Braconidae) 

Paul M. Marsh, Entomology Research Division , ARS 
U.S. Department of Agriculture, Washington, D.C. 

Ashmead (1900, p. 148) characterized the genus Callihormhis only 
as he included it in his key to the Ichneumon oidea, placing it in his 
subfamily Spathiinae, tribe Honniini. However, Callihormius belongs 
in the subfamily Doryctinae, tribe Doryctini, as I have defined it 
(Marsh, 1965). In the present study, I have interpreted the genus in 
a broader sense than has been done previously. For instance, one of 
the species described below, stigmatus, has a stigma in the male hind 
wing; my earlier diagnosis of the genus indicated that no stigma is 
present in the male (ibid., p. 697). The presence or absence of a 
stigma in the hind wing has been given generic value, but I believe 
that, as more genera of the Doryctinae are critically studied, this 
character will not always be generically significant. 

Callihormius contains five Nearctic species, four of which are de- 
scribed as new. The known hosts include larvae of beetles of the 
families Buprestidae and Cerambycidae. 

Genus Callihonuius Ashmead 

Callihormius Ashmead, 1900, p. 148. Type-species: Pambolus hifasciatus Ash- 
mead, 1892. Monob. and orig. desig. 

Head transverse; first flagellar segment longer than second; notauli absent or 
very weakly indicated; scutellar disc sometimes greatly convex or swollen; fore 
tibia with a row of 5-10 spines on anterior edge; fore wing with three cubital 
cells; recurrent vein entering first cubital cell; subdiscoideus leaving first brachial 
cell well above its middle, first brachial cell open at apex; media somewhat sinuate; 
fore wing with two or three dark transverse bands; radiella, cubitella, and post-